State preparation compilation error when optimization level is set to more than 1

[peachnuts]

from bqskit import MachineModel
from bqskit.qis.state.state import StateVector
from bqskit import compile

n = 2
coupling_graph = [(i, i + 1) for i in range(n - 1)]
model = MachineModel(n, coupling_graph=coupling_graph)
out_circuit = compile(StateVector([0, 1, 0, 0]), model=model, optimization_level=2)

It should get the circuit that prepares the state but I got the following error:

Traceback (most recent call last): File "/.venv/lib/python3.10/site-packages/bqskit/compiler/compiler.py", line 439, in _send_recv return self._recv_handle_log_error() File "/.venv/lib/python3.10/site-packages/bqskit/compiler/compiler.py", line 467, in _recv_handle_log_error raise RuntimeError(payload) RuntimeError: Traceback (most recent call last): File "/.venv/lib/python3.10/site-packages/bqskit/runtime/worker.py", line 462, in _try_step_next_ready_task future = task.step(self._get_desired_result(task)) File "/.venv/lib/python3.10/site-packages/bqskit/runtime/task.py", line 115, in step to_return = self.coro.send(send_val) File "/.venv/lib/python3.10/site-packages/bqskit/runtime/task.py", line 149, in run return await self.fnargs[0](*self.fnargs[1], **self.fnargs[2]) File "/.venv/lib/python3.10/site-packages/bqskit/compiler/task.py", line 54, in run await self.workflow.run(self.circuit, self.data) File "/.venv/lib/python3.10/site-packages/bqskit/compiler/workflow.py", line 75, in run await pass_obj.run(circuit, data) File "/.venv/lib/python3.10/site-packages/bqskit/passes/processing/scan.py", line 129, in run working_copy.instantiate(target, **instantiate_options) File "/.venv/lib/python3.10/site-packages/bqskit/ir/circuit.py", line 2901, in instantiate instantiater.multi_start_instantiate_inplace(self, target, multistarts) File "/.venv/lib/python3.10/site-packages/bqskit/ir/opt/instantiaters/minimization.py", line 110, in multi_start_instantiate_inplace params_list = [self.instantiate(circuit, target, x0) for x0 in starts] File "/.venv/lib/python3.10/site-packages/bqskit/ir/opt/instantiaters/minimization.py", line 110, in params_list = [self.instantiate(circuit, target, x0) for x0 in starts] File "/.venv/lib/python3.10/site-packages/bqskit/ir/opt/instantiaters/minimization.py", line 68, in instantiate return self.minimizer.minimize(cost, x0) TypeError: AttributeError: 'HilbertSchmidtCost' object has no attribute 'get_residuals'

I didn't get the error when setting the optimization level to 1.